If you think you might have a vacuum leak, just remove the oil filler cap while it is running. This will give a massive vacuum leak as the engine breather system runs under vacuum. If you notice a huge change, then you are not looking for a vacuum leak. Spraying carb cleaner around to find a leak is good, but keep a fire extinguisher handy just in case. Do not be tempted with brake cleaner, as a lot of the new brands are non-flammable and so will not give the desired result. Please don't use easy-start, you may well lose your car....and house....and wife.....